1. Field of the Invention
The present invention relates to a semiconductor manufacturing system and a semiconductor manufacturing system control device for use in the semiconductor manufacturing system, and more particularly, to a semiconductor manufacturing system capable of processing effectively with a processing device and to a semiconductor manufacturing system control device for use in such system.
2. Description of the Background Art
Various steps are involved in a semiconductor manufacturing line. The order in which the steps are performed varies depending on the lots. Thus, an operator has managed the steps according to the lots, and has provided the lots to an appropriate processing device. It is, however, possible, with a diffusion device for forming an impurity diffusion layer on the semiconductor manufacturing line, to process simultaneously a plurality of lots having the same conditions under which they are processed. Therefore, conventionally, the line operator would select the plurality of lots to be processed in the diffusion device and provide them into the diffusion device.
Moreover, when the processing in the diffusion device is completed, the lots are provided to a processing device (for example, for a photographic step or a chemical treatment step to embed the pattern) and undergo a prescribed processing. Beside these lots, a monitor lot (or a lot for an inspection of the diffusion process) is taken out from the diffusion device, and the monitor lot is inspected (for instance, to measure the film thickness) with the diffusion inspection device. When abnormality in quality is detected in the inspection of the monitor lot, the operator finds the lots undergoing the next processing step, and interrupts the processing for the lots.
The lots, however, are subjected to various processing based on their various step schedules. As a result, much time was required to select the lots having the same processing conditions upon the provision of the lots into the diffusion device. In addition, in the attempt to select the lots, there were times when lots having a different set of processing conditions were selected by mistake. Further, when a line operator is selecting the lots, the diffusion process may possibly be performed for a fewer number of lots than the maximum capacity of the diffusion device, which is inefficient. As a consequence, the processing efficiency was poor, and the product output was low.
Conventionally, the step preceding the diffusion step is a wet step in which a semiconductor wafer is immersed in a chemical. If the lots are not provided to the diffusion device immediately after the completion of the wet step, a natural oxide film forms on the surface of the semiconductor wafer. When the applied chemical is dry, the semiconductor wafer may no longer be suitable for use, leading to a possible reduction in the yield. In the above-described method in which a line operator manages the step schedules according to the lots, it was difficult to provide the lots to the diffusion device after the completion of the wet step in a short time.
If abnormality in quality is detected in the inspection of the monitor lot after the diffusion processing step, the lots undergoing the next processing step must be found, and the processing for the lots must be interrupted. It has become a problem that finding these lots took considerable time.
The present invention was made to solve the above problems. One object of the present invention is to provide a semiconductor manufacturing system having a high processing efficiency and a high product output.
Another object of the present invention is to provide a semiconductor manufacturing system capable of increasing the work efficiency of the operator.
A further object of the present invention is to provide a semiconductor manufacturing system having a high product yield.
According to one aspect of the present invention, a semiconductor manufacturing system control device is used in a semiconductor manufacturing system including a processing device for simultaneously processing a prescribed number of lots for which it is reserved, and a semiconductor manufacturing system control device connected to the processing device for managing the manufacturing steps. The semiconductor manufacturing system control device includes a lot processing step managing portion for managing the processing steps of the lots and determining whether the lots have arrived at the step of being processed by the processing device; a lot securing portion, connected to the lot processing step managing portion, for selecting, when the lots have arrived at the step of being processed by the processing device, a prescribed number of lots to be processed by the processing device under the same processing condition as the lots, instructing an operator to secure the prescribed number of lots selected, and determining whether the prescribed number of lots are secured; and a lot reservation portion connected to the lot securing portion and the processing device for reserving the processing device for the processing of the prescribed number of lots secured when the prescribed number of lots are secured.
The semiconductor manufacturing system control device secures the prescribed number of lots to be processed by the processing device in advance and reserves the processing device. The processing device processes the lots for which it is reserved. In this way, the processing device can always process the maximum number of lots it is capable of processing. In addition, processing of inappropriate lots can be prevented, leading to an effective processing, an increase in the product output, and an improved yield. Moreover, since the lots to be processed by the processing device is secured in advance, an operator can speedily provide the lots to the processing device. Therefore, the work time is reduced.
The semiconductor manufacturing system preferably further includes a stocker for storing the lots. The semiconductor manufacturing system control device further includes a work instruction portion for instructing the operator to hold in the stocker closest to the processing device the prescribed number of lots secured.
The lots are first collected in the stocker. Thus, by taking out the lots from the stocker and providing them to the processing device, the mistake the operator might make in providing the lots to the processing device can be eliminated, the work time is reduced, and the product yield is improved.
Preferably, the processing device further includes a request signal transmission portion connected to the semiconductor manufacturing system control device for transmitting to the semiconductor manufacturing system control device a request signal for requesting a prescribed number of lots when the processing of lots becomes possible, and a lot processing portion connected to the lot reservation portion for simultaneously processing the prescribed number of lots for which the reservation is made. The lot reservation portion includes a secured lot reservation portion connected to the lot securing portion and the processing device for reserving the processing device, when the prescribed number of lots are secured and the request signal is received, for the processing of the prescribed number of lots secured.
The processing of the lots is reserved according to the request signal from the processing device. Therefore, the operator can provide the lots to the processing device when the lots are secured and are ready for processing. Thus, the work time can be reduced.
Preferably, the semiconductor manufacturing system further includes an inspection device for inspecting the lots processed by the processing device. The semiconductor manufacturing system control device further includes a deterring portion connected to the inspection device for deterring the processing for the prescribed number of lots if a defect is found in the lots according to the result of the inspection with the inspection device.
The lots are advanced to the next respective steps only when it is decided that no defect is found as a result of the inspection with the inspection device. Thus, the operator can quickly deal with the problem when abnormality of product is detected, and a higher processing efficiency is achieved.
According to another aspect of the present invention, a semiconductor manufacturing system includes a processing device for simultaneously processing a prescribed number of lots for which it is reserved, and a semiconductor manufacturing system control device connected to the processing device for managing the manufacturing steps. The semiconductor manufacturing system control device includes a lot processing step managing portion for managing the processing steps of the lots and determining whether the lots have arrived at the step of being processed by the processing device; a lot securing portion, connected to the lot processing step managing portion, for selecting, when the lots have arrived at the step of being processed by the processing device, a prescribed number of lots to be processed by the processing device under the same processing condition as the lots, instructing an operator to secure the prescribed number of lots selected, and determining whether the prescribed number of lots are secured; and a lot reservation portion connected to the lot securing portion and the processing device for reserving the processing device for the processing of the prescribed number of lots secured when the prescribed number of lots are secured. The processing device includes a portion connected to the semiconductor manufacturing system control device for processing the prescribed number of lots for which it is reserved.
The semiconductor manufacturing system control device secures the prescribed number of lots to be processed by the processing device in advance and reserves the processing device. The processing device processes the lots for which it is reserved. In this way, the processing device can always process the maximum number of lots it is capable of processing. In addition, processing of inappropriate lots can be prevented, leading to an effective processing, an increase in the product output, and an improved yield. Moreover, since the lots to be processed by the processing device is secured in advance, an operator can speedily provide the lots to the processing device. Therefore, the work time is reduced.
According to a further aspect of the present invention, a method of controlling a semiconductor manufacturing system is a method for a semiconductor manufacturing system control device used in a semiconductor manufacturing system including a processing device for simultaneously processing a prescribed number of lots for which it is reserved, and a semiconductor manufacturing system control device connected to the processing device for managing the manufacturing steps. The method of controlling a semiconductor manufacturing system includes a step of determining whether the lots have arrived at the step of being processed by the processing device, a step of selecting, when the lots have arrived at the step of being processed by the processing device, a prescribed number of lots to be processed by the processing device under the same processing condition as the lots, instructing an operator to secure the prescribed number of lots selected, and determining whether the prescribed number of lots are secured, and a step of reserving the processing device for the processing of the prescribed number of lots secured when the prescribed number of lots are secured.
The semiconductor manufacturing system control device secures the prescribed number of lots to be processed by the processing device in advance and reserves the processing device. The processing device processes the lots for which it is reserved. In this way, the processing device can always process the maximum number of lots it is capable of processing. In addition, processing of inappropriate lots can be prevented, leading to an effective processing, an increase in the product output, and an improved yield. Moreover, since the lots to be processed by the processing device is secured in advance, an operator can speedily provide the lots to the processing device. Therefore, the work time is reduced.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.